This invention relates to jointed linkage support systems and more particularly, but not exclusively, to support systems for toys having lifelike joints.
Background and Summary of the Invention
There are many uses for a jointed linkage support system of the described type. The system may serve, for example, as a toy for making original geometric forms, or as a support for an object on display. However, a principal use of particular interest to the inventors is as a skeleton for a toy such as a doll, an animal, or the like. Toy animals and figures with movable necks, arms, legs, and spines may be made in many forms including skeletal figures, action figures, fashion dolls and stuffed animals covered in plush, simulated fur or vinyl.
For any of these and many other uses, the present jointed linkage support system may take on many different forms. For example, one might use the human body as a model representative of structures which may be built according to the invention. As a generality, the neck, shoulder, and hip joints may rotate and move through a cone of 360xc2x0 with the apex of the cone having an angle of up to nearly 90xc2x0 taken with respect to the central axis of the cone. The present invention will satisfy these requirements. Of course, other degrees of motion about the joints are also achievable in the invention.
On the other hand, knees, elbows, spines, and other body parts may bend in different ways. For example, the lower arm and leg may twist and rotate over a somewhat limited distance, but neither bends backward. The elbow and knee only bend back and forth so that the range of movement of the lower arm and leg is quite different from the range of movement of the upper arm and leg. The ankle has a limited rotational and back-and-forth movement. The same is true of the arm and wrist. Toes and fingers have movement which is apparent to anyone who flexes them. These types of motion can also be achieved with the present invention.
The new inventive linkage system of the present invention is preferably used to create an internal skeleton support system for a stuffed plush/vinyl toy and used to replace the malleable metal-wire insert traditionally used in stuffed toys often called xe2x80x9cbendablexe2x80x9d. The traditional xe2x80x9cbendablexe2x80x9d toy has used flexible wire inserts to give the toy a limited ability to bend in a somewhat random fashion. The present jointed linkage support system has a chain-like form, which is bendable in ways simulating actual body movements. This jointed linkage support system also overcomes the following problems common to metal-wire inserts:
Durability: The insert molding links that comprise the chain-like form of the new inventive linkage system provide many more play cycles than metal wire because the linkage system is not subject to metal wire fatigue. As a result of a number of play cycles in wire-supported bendable toys, the wire breaks. That breakage may, in turn, lead to cosmetic defects and create safety problems in the form of sharp, protruding broken wire tips.
Safety: It has been difficult to solve the potential safety problems created by the sharp points formed on the ends of wire materials used as inserts for toy figures and the like. The inventive jointed linkage support system uses molded parts which eliminate the sharp-point hazard present with metal-wire inserts. In fact, the linkage parts may be made with curved or rounded ends that add to the margin of safety over wire inserts.
Shape of Support System: Since this inventive linkage support system is produced by an injection molding process, it can provide a range of design and a degree of flexibility and strength not available in prior art systems.
Real-feel Feature: The insert-molding linkage parts have a rigidity that corresponds to the skeletons of real-life humans or animals, giving the feeling of real bones inside the soft stuffing materials, plush fabrics, vinyl skins, and the like. The prior art metal-wire inserts do not offer this unique real-feel feature. Likewise, the new inventive system may be used to form a display stand with legs and feet which may be raised or lowered, spread around or squeezed between obstacles. Hence, the invention offers a broad range of uses.
Accordingly, it is apparent that a preferred jointed linkage support system should provide for many alternative degrees of freedom. This need for flexibility of design creates a series of challenges. If the jointed linkage is created from an assembly of many loose parts as in conventional systems, the loose parts may have to be manually interconnected, which creates excessive labor costs. Or, if automatic assembly machines are used, they may be prohibitively expensive, especially if they must assemble a number of parts having different sizes and shapes. If such an automatic assembly machine is limited to assembling only parts having the same configurations, the freedom to design new devices using a linkage having many different configurations is lost.
Thus, there is a need to provide a molded, jointed linkage support system which is already assembled when it emerges from the mold. If the system is to be used as a skeleton for toys, there should be a negligible cost differential between the inventive jointed linkage support system and the malleable metal wire inserts used heretofore.
Another desirable feature is to include a switch integrally formed with the molded, jointed linkage support system. Such a switch may be actuated by relative movement of various components of the linkage support system. The switch may be used to activate special features associated with the jointed linkage support system, such as turning on lights, activating synthesized or recorded speech, or other sounds and the like.
Accordingly, an object of the invention is to provide a jointed linkage support system having the foregoing features. A general object of the invention is to provide a general-purpose system having many different uses. A particular object of the invention is to provide a jointed linkage system which may be used as a skeleton for toys.
Another object is to provide a method of making a joint having a controlled degree of freedom of movement.
Yet another object is to provide a molded jointed linkage support system which is already assembled as it emerges from the mold.
Still another object is to provide a molded jointed linkage support system having an integrally formed switch.
In keeping with an aspect of the invention, these and other objects are accomplished by providing a molded product made of plastics having different meeting temperatures. Using a ball and socket joint, by way of example, the ball part is first formed in any desired fashion such as molding in a separate mold plate. Preferably, the ball is made of a plastic material which has a first melting temperature. An injection mold plate is then provided with communicating cavities in the socket contours. The previously formed ball parts are placed in the corresponding socket cavities of the second mold plate so that the balls effectively become part of the second mold plate, with the balls projecting into the cavities corresponding to the sockets. The mold plate cavities corresponding to the sockets are charged with a plastic having a melting temperature which is lower than the melting temperature of the plastic forming the balls, referred to below as xe2x80x9clow temperature plasticxe2x80x9d. Thus, after the plastic in the socket cavities solidifies, sockets are molded around the balls. The lower melting point of the plastic material enables sockets to solidify around the balls without fusing to the balls or causing any distortion of the balls.
If a jointed linkage support system is to be formed in accordance with the invention, a series of communicating mold cavities may be configured to provide a series of jointed linkages that provide different degrees of freedom of movement. Hence, unique jointed linkage support systems may be provided which are already assembled as they emerge from the mold. In the preferred usage, the communicating cavities are configured to provide jointed linkages having the geometry of a skeleton corresponding to the geometry of a skeleton of a human or animal which the toy, stuffed and covered with plush or vinyl, simulates.
In an embodiment of the invention a jointed linkage support system is provided which includes a motion actuated switch. The switch may be integrally formed with the jointed linkage support system, and the switch opened and closed by relative movement between various components of the jointed linkage support system.
The principles of the invention and a preferred embodiment thereof may be best understood from the following specification taken with the attached drawings.